These icons should match the Nuvola icons already on our Main Page. Ideally, they should be SVG (don't worry, the SVG rendering bug is temporary) and be sharp, clear and recognizable from 24x24 px up to 128x128 px. See Wikipedia:Wikipedia:Picture tutorial for help uploading.
Car with bright paint, on which User:Seahen will base icons for Category:New car buying, Category:Car leasing and Category:Used car buying
Basket of groceries, for Category:Food & Nutrition, and individual pieces of food for its immediate sub-categories